Cognitive Coordinating Behaviors in Multitasking Web Search Jia Tina Du School of Computer and Information Science, University of South Australia GPO BOX 2471, Mawson Lakes Campus, Adelaide, SA 5001, Australia
[email protected] ABSTRACT This paper investigates how users cognitively coordinate multitasking Web search across different information search problems. The analysis suggests that (1) multitasking is a prevalent Web search behavior including both sequential multitasking (31%) and parallel multitasking (69%); (2) multitasking is performed through a task switching process; and (3) such a process is supported and underpinned by cognitive coordination mechanisms and strategy coordination.
Categories and Subject Descriptors H.3.3 [Information Storage and Retrieval]: Information Search and Retrieval – relevance feedback, search process.
General Terms: Human Factors, Performance, Theory. Keywords:
Cognitive coordination, Information problem, Multitasking, Task switching, Web search.
1. INTRODUCTION Discovering the multitasking behavior of Web users is a growing research area. Recent Web query log studies show that multitask searching is a common human information retrieval behavior. Many users conduct information searching on multiple related or unrelated topics and also switch between the topics, with a mean of 2.1 topic changes per search session [5]. Buzikashvili’s multitasking study based on the automatic task session detection procedure further reported that more than 98% search sessions were sequential execution, during which a searcher executed tasks one-by-one. This is in contrast to only 1% parallel execution, during which a user interrupted one task, started and completed the second task, and returned to the interrupted task later [1]. Unfortunately, previous multitasking Web search studies did not examine the type and complexity of multiple search tasks switching in detail. Existing research limits findings to information tasks level. The literature of psychology and cognitive sciences, however demonstrates that multitasking behavior is correlated closely to humans’ cognitive processing and coordination capabilities [2]. The cognitive executive control systems govern processes including the selection, initiation, execution and termination of each task [4]. People could consciously trade-off performing one task for the other stemmed from their coordination capability. Cognitive coordination allows humans to manage the dependencies among tasks and the resources available [3]. The research presented in this poster is part of an investigation of multitasking and coordination behavior in Web search. This poster examines the following research questions: (1) what are characteristics of multitasking and task switching during Web search? and (2) how do users cognitively coordinate between multiple information search problems? Copyright is held by the author/owner(s). SIGIR’11, July 24–28, 2011, Beijing, China. ACM 978-1-4503-0757-4/11/07.
2. METHODOGLY An empirical study was conducted in a controlled lab environment to explore characteristics of multitasking behavior and the underlying cognitive coordination process during multitasking Web searches. The study participants were 42 graduate students (24 males and 18 females), with an average age of 29 years. They came from diverse disciplinary programs, ranging from Science and Technology, Business, Engineering, Education, and Health. Different from search queries, information problems are of importance to interactive information retrieval because they provide a context implying users’ motivations, constraints, searching scope, and affecting query formulation and relevance judgments. In order to investigate multitasking behavior, each study participant was asked to search on three individual information problems from their real work and life during a onehour search period. These planned information problems were called original information problems (OIP). In total 126 OIPs across 15 various topic areas were observed over the Web searches, amounting to approximately 35 hours. Study participants were required to verbalize their thoughts, motivations/reasons, and actions as they were searching on the Web. The search logs and think-aloud audio data were recorded by Camtasia screen software. The analysis unit was each information search problem instead of search query.
3. RESULTS AND DISCUSSION 3.1 Characteristics of Multitasking and Task Switching during Web Search Table 1 shows characteristics of multitasking Web search sessions based on quantitative analysis of the search logs. Beyond three OIPs planned beforehand, almost 71% of the study participants developed evolving information problems (EIP) during the process of the current Web searches. An EIP was detected by topic shifts. Compared to an OIP, an EIP was represented as changed or totally new problems. The number of EIPs ranged from zero to eight, with a mean number of 2 per search. That is, each study participant searched on 5 information problems (OIP + EIP) on average. Table 1. Characteristics of multitasking behavior
Table 2. Multitasking as task switching during Web search
In multitasking Web search, the number of submitted search queries varied from 4 to 39, with a mean of 18; the number of employed Web search systems varied from 1 to 10, with a mean of 4; and the mean number of browsed windows/tabs was 17 (Table 1). The results show the complexity of multitasking behavior involving users’ interactions with Web technologies. The study participants were found to switch between searching on original information problems (SOIP) and searching on evolving information problems (SEIP). A process of 275 searching task switches over the 42 Web searches was identified, with 6 task switches per multitasking search. People handled the demands of multiple tasks sequentially or interleaving through task switching, namely, sequential multitasking or parallel multitasking (Table 2), accounting for 31% and 69% of Web searches, respectively. For sequential multitasking, study participants spent an average of 12 minutes per task before switching to another task. In contrast, parallel multitasking study participants spent an average of only 8 minutes on one task before switching to another.
3.2 Cognitive Coordination during Multitasking Web Search Based on the content analysis of search-utterance segments (combining search logs and transcribed think-aloud audio data), we found that the occurrence of cognitive coordination played an active role in multitasking and task switching activities. Multitasking and task switching were underpinned and supported by cognitive coordination processes including coordination mechanism and strategy coordination. Coordination mechanism involved a conscious reasoning and judging process – most of these were content relevance feedback of making relevance judgments on the returned results, and selflearning and regulating process of making sense of the gathered information. Coordination mechanism was identified as the most important reason for users’ task switching behavior (Table 2 last column, 45% for sequential multitasking and 95% for parallel multitasking). Multitasking Web search was cognitively constructed as users learned with information attainment during the process. Evidence can be elicited from study participants’ utterance, such as “I have found enough related information, I’d move on to next information problem” (SP37), “I did not think the information was useful, I might change the keywords” (SP13), and “since this problem [OIP3] is about a tour available in Malaysia, I just quickly check the visitor visa [EIP1]” (SP8). Strategy coordination was a strategic plan for solving multiple information problems within the resources available. Strategy coordination was viewed as the second most important reason
for users’ task switching behavior (Table 2 last column, 17% for sequential multitasking and 45% for parallel multitasking). Two types of strategies were identified: problem specific strategy (PSS) and global strategy (GS). The PSS was the collection of tactics on usable Web searching tools for each information search problem, including the selection of Web search systems and the adoption of search queries, etc. The GS was an overall plan guiding the whole searching process and was presented as users’ decisions on the allocation of searching time between multiple information search problems. For instance, “still 40 minutes left, I’d like to back to find out more detailed information on my first information problem” (SP6). Other two minor reasons for parallel multitasking and task switching were interest shift (5%) and visual cues (5%). Users switched from one searching task to another due to being bored with the current information problem, or just “followed his or her nose” unconsciously.
4. CONCLUSIONS Multitasking Web search not only takes place at the physical task level, but also at the cognitive coordination level. It is a behavior associated closely with humans’ cognitive processing including relevance judgment, self-learning and regulating process, and cognitive strategy of time allocation. Multitasking and coordination processes could be supported by different combinations of various retrieval techniques. Future studies will make use of these findings in Web search systems design.
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